Description: In the previous application, this resource was called the Protein and Nucleic Acid Structure Core Facility. The purpose of the resource is to provide computational and graphics support to Center members in the computer analysis of protein and nucleic acid sequences and structures. The resource provides computing hardware, software, network access, databases, and training and consultation for specific problems in the analysis of sequences and three-dimensional (3-D) structures of proteins and nucleic acids. The resource is organized into two physically separate but interrelated computing services. These units serve researchers that need to analyze sequences to establish homologies or analyze secondary structures and to model 3-D structures, respectively The Research and Instructional Biocomputing Service (RIBS) is directed by Dr. R. Simons and services include nucleic acid and protein sequence analyses; workshops for faculty and research staff; consultation on specific problems; and communication services. The computer facility is directed by Dr. D. Eisenberg and provides computational services related to 3-D protein models, determining 3-D protein and nucleic acid structures by x-ray and NMR methods, and molecular modeling. Graphics services are also provided and software is maintained for analysis of amino acid sequences in determining 3-D structures. Databases are maintained for 3-D structures, sequences, and profiles, including structure and sequence databases that are not otherwise available. Access to these computing facilities is by request of users, and appropriate consultation and collaboration is provided. No significant delays have been reported in providing services. RIBS charges an annual fee of $480 per researcher and allocates one account for each lab member who desires access. The computer facility charges $900 per month for heavy users and $250 per month for light users.